Abstract
Background: Helicobacter pylori colonizes the human gastric mucosa through outer membrane proteins (OMPs), particularly the adhesins BabA and BabB, which recognize host blood group antigens and mediate bacterial attachment and persistent colonization; importantly, structural and genetic studies have confirmed substantial polymorphisms in these adhesins that may affect their functional properties and contribute to differences in the clinical outcomes of infection. Therefore, the present study aimed to investigate the prevalence and genetic diversity of babA/babB variants in H. pylori isolates obtained from Jordanian patients and to evaluate their association with different gastric pathological conditions. Methods: A total of 106 gastric mucosal biopsies were collected from patients with gastric symptoms at two major hospitals in Jordan. Specimens underwent endoscopic evaluation, rapid urease testing (RUT), and histopathological examination according to the Sydney classification system. H. pylori detection was performed using real-time PCR targeting 16S rRNA and universal bab genes using novel primers designed to amplify both babA and babB variants. Conventional PCR was used for specific BabA and BabB gene amplification, followed by sequencing analysis of BabB variants. Results: A total of 106 patients were enrolled, with a mean age of 40.2 ± 15.9 years. H. pylori was detected in 76 (71.7%), 83 (78.3%), and 79 (74.5%) cases by the Rapid Urease Test (RUT), histopathology, and 16S rRNA qPCR, respectively. Using histopathology as the reference method, 16S rRNA qPCR demonstrated a sensitivity of 95.2%, compared with 91.6% for RUT. Among the 83 histopathology-positive cases, the universal bab gene was detected in 72 (86.7%), of which 53/72 (73.6%) were positive according to babB-specific PCR. Among patients with chronic gastritis, universal bab positivity increased progressively from 82.5% in mild to 88.5% in moderate and 93.3% in severe gastritis, whereas babB positivity increased from 50.0% to 76.9% and 80.0%, respectively. Sequencing of 40 babB-positive samples identified 27 distinct babB sequence profiles, with CHI-023 and LIM-008 being the most frequently identified reference sequence matches (10.0% each), highlighting substantial genetic diversity within the analyzed babB region. Conclusions: The findings demonstrate high diagnostic performance of 16S rRNA qPCR and RUT relative to histopathology, together with substantial genetic diversity within the analyzed babB region.